TopPageTopics 2006 > 2006-8


2008/05/28(Wed) 15:05

Sensitive measurements of diamagnetic susceptibility under magnetic levitation conditions



We have demonstrated sensitive measurements of diamagnetic susceptibility under the magnetic levitation state, which is very sensitive to the change of the magnetic susceptibility. A single crystal of benzophenone was levitated in a temperature controlled thermostatic bath combined with a hybrid magnet. The levitating position of the sample moved upward as increasing temperature, and the sample was returned to the initial position by changing magnetic filed slightly. The magnetic susceptibility was evaluated from the B(B/z) at the sample position. The change of the susceptibility, ∆χg = 0.0022×10−9 m3/kg (0.035%) as the minimum value could be detected.

IMR, Tohoku University: K. Takahashi, I. Mogi, S. Awaji, K. Watanabe

磁気浮上状態が磁化率の変化に敏感であることを利用し,反磁性磁化率の高感度測定を試みた.試料には有機結晶ベンゾフェノンの単結晶(融点48~50˚C)を用い,加熱による質量磁化率の変化を測定した.磁化率の変化によって上昇する試料に対し,ハイブリッドマグネットの磁場を僅かに変えながら浮上位置を一定に保つ操作を行い,試料位置での磁気力場B(B/z)の値から磁化率を見積もった.その結果,最も変化量の小さいところで∆χg = 0.0022×10−9 m3/kg,変化率としては 0.035%程度のわずかな磁化率変化を測定することに成功した.

東北大学金属材料研究所:高橋弘紀,茂木 巌,淡路 智,渡辺和雄